000 AXNT20 KNHC 270603 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 203 AM EDT WED JUL 27 2016 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlantic from 09N-19N with axis near 27W, moving at 15 kt within the last 24 hours. Meteosat composite imagery show Saharan dry air and dust in the northern wave environment. Moderate moist air from surface to 850 mb and divergent flow in the middle to upper levels support scattered moderate convection from 07N-11N between 22W and 30W. A tropical wave is in the central Atlantic from 09N-17N with axis near 40W, moving west at 20 kt within the last 24 hours. CIRA LPW imagery show mainly dry air from the surface to 850 mb associated with this wave. The dry air is due to the presence of abundant Saharan dry air and dust, which is hindering convection at the time. A tropical wave is in the central Caribbean from 11N-21N with axis near 69W, moving west at 20 kt within the last 24 hours. The wave is associated with shallow moisture according to CIRA LPW imagery. Aloft, water vapor imagery show strong subsidence across the central-southern Caribbean, which is inhibiting convection in that region at the time. However, the wave supports scattered to isolated showers over Hispaniola and its coastal waters. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 18N16W to 11N24W to 10N34W to 08N45W. The ITCZ begins near 08N45W and continues to the coast of Guyana near 06N57W. Aside from the convection related to the tropical wave in the east Atlantic, heavy showers and tstms are from 06N-19N E of 19W. Scattered showers are from 02N-08N between 30W and 44W. ...DISCUSSION... GULF OF MEXICO... A middle to upper level low covers the NW basin tonight while a broad upper level inverted trough formerly in the W Caribbean has moved to the E Gulf waters, however associated with dry air subsidence. This dry air is limiting the convection to isolated showers and tstms E of a line from 29N83W to 22N87W. Moisture inflow from the Caribbean by SE flow and the low aloft support scattered to isolated showers N of 23N W of 86W. In the SW Gulf, a surface trough off the western Yucatan Peninsula support scattered showers and tstms in the eastern Gulf of Campeche S of 20N. Otherwise, mainly E-SE moderate wind covers the basin due to weak surface ridging. The exception is the Bay of Campeche where NE moderate to fresh flow is noticed. Weak surface pressure and return flow will prevail the next two days. CARIBBEAN SEA... The short-wave upper trough formerly over the central Caribbean is now over eastern Cuba, thus supporting isolated showers and tstms over the Island coastal waters. To the west, the eastern portion of a broad inverted upper-level trough supports isolated showers and tstms in the NW Caribbean, including the western Gulf of Honduras. In the SW basin, the monsoon trough supports heavy showers and tstms within 120 nm of the coast of northern Panama, Costa Rica and southern Nicaragua. A tropical wave is moving across the central Caribbean where it generates scattered to isolated showers across Hispaniola and adjacent waters. See the tropical waves section above for further details. Scatterometer data depict fresh to strong winds in the south-central basin S of 16N and moderate trades elsewhere. Showers will continue across Hispaniola tonight as the wave continue to move westward. The next tropical wave will enter the east Caribbean during the weekend. ...HISPANIOLA... A tropical wave is moving across the central Caribbean where it generates scattered to isolated showers across Hispaniola and adjacent waters. Convection associated with this wave is expected to continue through Wednesday evening. ATLANTIC OCEAN... Two tropical waves are moving across the basin and a third wave is over the central Caribbean, but extending to 21N. Please refer to the tropical waves section for more details. With little support aloft, a stationary front in the central Atlantic will start to weaken. The tail of this front extends to the area of discussion from 30N55W SW to 26N62W and support isolated showers within 60 nm either side of the boundary. Surface high pressure is across the remainder basin being anchored by a 1033 mb high centered N of the Azores Islands. Expect for the surface ridge to persist through the next 24 hours and the front to dissipate. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS